果胶酶ROHAPECT D5S对猕猴桃取汗和澄清的影响

研究了果胶酶ROHAPECTD5S对猕猴桃出汁率、粘度、澄清度和冷热稳定性的影响。结果表明,此酶可以极大地改进猕猴桃果浆的出汁率和降低果汁粘度,使果汁的澄清度加大,对冷冻和加热的稳定性加强,适合用作弥猴桃汁的加工,对猕猴桃浆的最佳应用条件为3PA/100g果浆（相当于干酶60g/1000kg果浆）,45℃下60min。     

响应面法优化猕猴桃果浆酶解工艺参数研究

本文研究果胶酶反应温度和作用时间及酶用量对猕猴桃果浆出汁率、果汁澄清度和乙醇不溶物的影响,采用通用旋转设计和响应面分析猕猴桃果浆酶解最优条件。结果表明,猕猴桃果浆的最佳酶解条件为:反应温度为45℃,作用时间为113min,果胶酶用量为0.013%,在此条件下,猕猴桃果浆预测出汁率达到83.30%,乙醇不溶物0.98g/100ml,果汁的澄清度为81.47%。验证试验表明,响应面优化后得到猕猴桃果浆出汁率、果汁澄清度和乙醇不溶物回归方程的相关系数分别为0.958、0.904和0.922。     

果胶酶在猕猴桃果汁处理中的应用

研究了采用果胶酶HC澄清猕猴桃果汁时的工艺条件和在猕猴桃果浆榨汗中的应用，并通过实验得出结论，澄清时，酶HC加量40mg/L,pH3-4，温度40－50℃，处理150min，用此处理工艺所得猕猴桃汁的Vc损失较小，透光率较高，果胶基本分解完全在果浆榨汁中，也只需采用相同的用量就能使果汁的粘度下降71％，出汁率提高10％以上，而营养物质基本无损耗。     

响应面法优化枸杞果浆酶解工艺参数的研究

以枸杞鲜果为原料经过打浆制得枸杞果浆,采用果胶酶酶解枸杞果浆以提高出汁率及澄清度。在单因素实验基础上,采用响应面法优化枸杞果浆酶解工艺条件,选取初始pH、果胶酶用量、酶解温度及酶解时间为影响因子,以枸杞果浆的出汁率及澄清度为响应值,应用Box-behnken试验设计建立了二次回归方程的数学模型,进行响应面分析。结果表明:最佳酶解工艺参数为初始pH3.9,果胶酶用量43.0mg/L,酶解温度47.0℃,酶解时间1.0h,在此条件下酶解的枸杞果浆出汁率为80.68%,澄清度为94.1%。     

果胶酶与半纤维素酶复合酶解制备费约果果汁的工艺优化

为减少费约果细胞壁中果胶和半纤维素等物质对果汁品质的负面影响,提高果汁出汁率,本文研究了复合酶(半纤维素酶和果胶酶)比例、加酶量、温度、时间对“Unique U-100”费约果果汁出汁率和可溶性固形物的影响。在单因素实验的基础上,进行四因素三水平的响应面优化。结果显示：在复合酶(半纤维素酶/果胶酶)比例为2.14:1,加酶量19.6 g/L,酶解温度56.8℃,酶解时间92 min的条件下,费约果果实出汁率最高,为79.5%,与模型预测值相对误差为5.67%;果汁中可溶性固形物含量为15.7%,与模型预测值相对误差为0.83%。此外,与直接压榨的费约果果汁相比,酶解后的果汁表现出更高的澄清度、总酚含量(24.4 mg GAE/100 g)和V_C含量(2.42 mg/100 g)。因此,本研究优化了复合酶酶解制备费约果果汁的工艺,提高费约果果汁出汁率和营养品质,可为后续费约果果汁深加工提供理论依据。     

沙田柚果浆酶解工艺条件的研究

以梅县沙田柚为原料,利用果胶酶处理柚果浆,考察酶解温度、酶解时间及酶添加量对果浆出汁率的影响,优化沙田柚果浆酶解工艺条件。结果表明,最佳酶解条件:酶解温度40～45℃,酶解时间3h,酶添加量75～100mg/L,此时出汁率在80%以上;比较酶解前后果汁的营养成分的变化,果汁可溶性固形物提高了0.6 oBix,还原糖含量由9.418g/L提高到10.30g/L,出汁率提高了18.23%,果汁黏度由30mPa.s显著下降至2mPa.s,VC损失率为28.2%,同时果汁透光率也显著提高,而对果汁总酸、pH值等基本无影响。     

果浆酶和果胶酶对猕猴桃出汁率的影响

为制取猕猴桃汁,通过单因素和正交试验,以出汁率、VC保存率和果汁色泽香气变化为指标,用果浆酶和果胶酶对猕猴桃进行酶解处理,探索更适合的猕猴桃制汁工艺条件。结果表明：两种酶都能大幅提高猕猴桃的出汁率,果胶酶酶解条件较剧烈,虽出汁率较高,但对VC含量和果汁色泽香气影响较大;果浆酶酶解条件较温和,总体指标较好,最佳酶解条件为酶解温度30℃、果浆酶加酶量10000U/kg、酶解时间2h、出汁率0.853mL/g,VC保存率67%。果浆酶更适合猕猴桃果汁的制取。     

酶制剂在澄清香蕉汁加工中的应用

利用淀粉酶、果胶酶制剂处理香蕉果浆,结果表明:在55℃下,香蕉果浆中加入0.4％的淀粉酶酶解30min,可明显提高香蕉果汁的得汁率;在45℃下,香蕉果汁中加入0.015％的果胶酶酶解60min,可明显提高香蕉果汁的澄清度。     

树莓澄清果汁的加工工艺

研究了红树莓澄清果汁的加工工艺,酶解处理的酶用量,酶解温度,酶解时间的单因素试验以及酶用量,酶解时间和红树莓品种的正交优化试验表明,树莓果浆经酶解后,出汁率有较大提高,果汁澄清度也较好。最佳酶处理条件为加酶量3.5‰,酶处理温度45℃,时间4h;在所试验的3个品种中,维拉米综合指标最好,表现为出汁率高,可溶性固形物,总糖,VC含量均较高;树莓汁调配时一般不需加酸,只需补充糖即可达到较好的口感风味。     

图解法优化荔枝果浆酶解澄清的工艺

为了制备荔枝澄清果汁,探讨不同的果胶酶用量(质量分数0.02％～0.06％,m/m),酶解时间(1～3h)和温度(35～55℃)等工艺参数对荔枝果汁的出汁率和澄清度的影响.结果表明果胶酶处理可以提高荔枝果汁的出汁率和澄清度.通过响应面试验设计分析和图解法优化途径,获得果胶酶制备荔枝澄清果汁的较优工艺条件,在酶用量0.045％～0.05％(m/m),温度46～50℃和时间2.0～2.5h时,荔枝果汁的出汁率和透光率的预测值分别为90.40％和91.10％.经实验验证,预测值与实验值相符.     

Calcium Supplementation and Processing Variable Effects on Orange Juice Quality

Untreated, pectinesterase treated, low pulp, and pectinase treated orange juices were fortified to 20% RDA of calcium with calcium carbonate or calcium phosphate/lactate (75/25). Neither calcium supplement adversely affected flavor, cloud density, settling pulp, or viscosity in untreated, low pulp, or pectinase treated juices. PME exposed orange juice held 4 hr before pasteurization and calcium supplementation had less cloudy density, increased viscosity and more settling pulp. Calcium carbonate fortified PME exposed and pectinase treated juices had lower flavor scores, while calcium phosphate suspensions caused slightly lower color scores of all juices.     

Evaluation of enzymatic treatment of peach juice using response surface methodology

BACKGROUND: This work aimed to assess peach juice clarification using enzymatic treatment. The enzymatic hydrolysis was performed to reduce the juice viscosity and pulp content, and consequently to increase juice extraction. The hydrolysis conditions were optimized by the response surface methodology, where the influence of temperature, amount and type of enzyme and time of reaction were investigated. RESULTS: Two commercial pectinase preparations (AFP L3 and ULTRA SP WOP from Novozymes) as well as a cellulase (R10 from Onozuka) were tested. The hydrolysis using Pectinex AFP L3 (Novozymes) at 25 °C for 60 min presented the best results of pulp (48%) and viscosity (68%) reduction. CONCLUSION: Physical and chemical analyses showed that the enzymatic treatment is effective for reduction of peach pulp viscosity, pulp content and turbidity and does not influence other juice parameters such as pH, total acidity, vitamin C and soluble solids. Copyright © 2007 Society of Chemical Industry     

Enzymatic hydrolysis of carrot for extraction of a cloud-stable juice

The influence of various enzymes on the cell wall structure of carrots (Daucus carrota) was examined and related to changes in the juice extracted from the pulp with respect to volume, solids content, pH and viscosity. Crude preparations of cellulase (EC 3.2.1.4), hemicellulase, pectinase (EC 3.2.1.15), pectinesterase (EC 3.1.1.11) and an industrial grade pectinase/cellulase preparation (Rohament PC), all exhibiting cellulolytic as well as pectinolytic action, were used either singly or in combinations. Polarizing microscopy revealed a gradual loss of birefringence from the cell walls indicating degradation of ordered structure by all of the enzymes. The time for loss of birefringence was significantly correlated with the pectinase activity but not with the cellulase activity, suggesting that the presence of pectic substances is important in maintaining the ordered structure of the cell wall in carrot. Alterations to cell wall structure by pectinase were confirmed by scanning electon microscopy. Hydrolytic activity against carrots as measured by the increase in yield of juice could be predicted from the pectinase and cellulase activities through a linear regression equation (R = +0.72; P < 0.01) but the pectinolytic action was the most important factor. The yield of juice from the control carrot was 50.5% of the wet pulp mass with a total solids content of 7.9%, viscosity of 2.9 centistokes and a pH value of 5.65. Application of the enzyme preparations to the pulp (268–455 mg/kg) increased the volume of juice extracted, with the industrial grade preparation (440 mg/kg) yielding 50% more juice than the control for a 30-min incubation at 50 °C.     

绿茶猕猴桃复合饮料的试验与开发

以新鲜信阳毛尖茶为原料,在80℃、15min条件下萃取出绿茶汁,再以3：1的比例复合绿茶汁与猕猴桃汁,添加果胶酶40mg／L,在40℃下酶解150min,澄清过滤后加入12％的白砂糖,经137℃、15s UHT杀菌制成一种新型复合茶饮料。     

果胶酶制剂在澄清苹果汁加工中的应用研究

利用果胶酶制剂处理苹果(品种:国光)、果浆、果汁,结果表明:0.1％的Pectinex Ultra SP果胶酶处理可明显地提高出汁率、可溶性固形物和透光度;降低pH值和相对粘度,处理效果随作用时间增加而增加,对不同贮藏期的苹果处理效果不同。0.1％的TL-enzyme果胶酶与0.1％的纤维素酶结合处理的效果大于0.1％的TL-enzyme果胶酶单独处理的效果。在20～22℃,汁中添加不低于0.1％的黑曲霉(As 3.316)果胶酶或不低于0.001％的Ultrazym100G果胶酶,可分别在8小时和6小时内使果汁澄清;处理温度提高或酶浓度加大,澄清时间缩短。用Ultrazym100G果胶酶澄清的汁,其糖分、滴定酸含量没有明显变化,单宁物质含量降低,矿质元素和沉淀中粗蛋白含量发生变化。     

番茄制品加工工艺研究进展

就近年来国内外在番茄制品加工工艺方面的研究进行了综述。从提高产品粘稠度、浓缩、浸钙硬化等方面 ,分别介绍了微波加热、高压处理、超滤浓缩、反渗透浓缩、冷冻浓缩以及优化浸钙工艺等技术应用于番茄制品加工的研究近况     

果胶酶酶解红枣浆工艺研究

以市售和田大枣为原料,利用果胶酶处理红枣浆,以提高红枣浆出汁率。通过单因素试验得到在酶解温度30℃~50℃范围内、酶解pH 4.5~5.5、果胶酶添加量0.01%~0.03%、酶解时间60 min~80 min红枣浆出汁率较高,酶解效果较好;通过正交试验得到果胶酶处理红枣浆最佳工艺条件为酶解温度40℃,酶解pH 5.5,果胶酶添加量0.03%,酶解时间60 min,此条件下红枣浆出汁率为87.5%,比未添加果胶酶进行酶解提高了19%。     

酶对荔枝液化效果的研究

研究了纤维素酶、半纤维素酶、果胶酶对荔枝果肉的液化效果。通过试验发现果胶酶、纤维素酶单一使用时的液化效果较好。果胶酶在用量为1%时可达到33%的汁液得率。纤维素酶在用量为0.9%时可得到25%的汁液得率。半纤维素酶在用量低时汁液得率较低,但在用量为0.8%以上时可达到与纤维素酶同样的汁液得率。纤维素酶、半纤维素酶、果胶酶几种酶复合使用时,以半纤维素酶用量为0.6%、纤维素酶用量为0.4%、果胶酶用量为1.0%时的液化效果最佳。     

体外模拟胃肠消化过程中猕猴桃抗氧化成分及活性的变化

研究猕猴桃果浆和果汁在体外模拟胃肠消化过程中多酚黄酮类物质含量及抗氧化活性的变化规律。采用铁还原力,以及DPPH自由基、超氧阴离子自由基、羟自由基清除法测定抗氧化性。结果显示,消化后多酚和黄酮物质释放量增加。果浆消化后最大释放量分别为消化前的1.62倍和2.40倍;果汁消化后多酚、黄酮的最大释放量分别是消化前的1.63倍和2.90倍。果汁、果浆的DPPH自由基、超氧阴离子自由基和羟自由基清除率以及铁还原力均在模拟胃消化1 h和肠消化1 h后达到最大值,随后开始下降并趋于稳定。果浆和果汁的抗氧化能力虽不同,但变化规律类似。研究表明,模拟胃肠消化能促进猕猴桃多酚、黄酮的释放,提高抗氧化活性。